Display device

This application claims priority from Korean Patent Application No. 10-2023-0045846 filed on Apr. 7, 2023 in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. 119, the contents of which in its entirety are herein incorporated by reference.

The present disclosure relates to a display device, and more particularly, to a display device in which an output of a gate driving circuit is stabilized and a size of the gate driving circuit is decreased.

A thin film transistor (TFT) has been used in various fields. In particular, it has been used as a switching and driving element in flat display devices such as liquid crystal displays (LCD), organic light emitting diode (OLED) displays, and electrophoretic displays.

Aspects of the present disclosure provide a display device in which an output of a gate driving circuit is stabilized and a size of the gate driving circuit is decreased.

However, aspects of the present disclosure are not restricted to those set forth herein. The above and other aspects of the present disclosure will become more apparent to one of ordinary skill in the art to which the present disclosure pertains by referencing the detailed description of the present disclosure given below.

In one aspect, the disclosure pertains to a display device including: a substrate having a display area and a non-display area; a pixel disposed in the display area of the substrate; and a gate driving circuit disposed in the non-display area of the substrate and connected to a transistor of the pixel, wherein the gate driving circuit comprises: a node control unit; a pull-up transistor connected to a set node of the node control unit through a gate electrode; and a pull-down transistor connected to a reset node of the node control unit through a gate electrode, wherein a width of a first channel region of the pull-up transistor is greater than a width of a second channel region of the pull-down transistor.

The display device may further include an active layer comprising the first channel region and the second channel region.

The active layer may include: a stem portion; a first branch portion extending from an upper edge of the stem portion along a first direction; a second branch portion extending from a center of the stem portion along the first direction; a third branch portion extending from a lower edge of the stem portion along the first direction; a first finger portion extending between the first branch portion and the second branch portion and comprising the first channel region; and a second finger portion extending between the second branch portion and the third branch portion and comprising the second channel region.

In an embodiment, more than one of the first finger portion may be provided between the first branch portion and the second branch portion.

In an embodiment, more than one of the second finger portion may be provided between the second branch portion and the third branch portion.

The display device may further include a first gate pattern overlapping the first finger portion.

In an embodiment, the first gate pattern may include a first gate electrode of the pull-up transistor.

The first channel region may be defined by an overlapping of the first gate electrode and the first finger portion.

In an embodiment, the display device may include a first light blocking layer (BML) overlapping the first finger portion and the first gate electrode.

The first light blocking layer may include a first counter gate electrode overlapping the first gate electrode.

The first gate electrode and the first counter gate electrode may be connected through a contact hole in an insulating layer.

In an embodiment, the second gate pattern may include a second gate electrode of the pull-down transistor.

In an embodiment, the second channel region may be defined by an overlapping of the second gate electrode and the second finger portion.

In an embodiment, the display device may include a second light blocking layer overlapping the second finger portion and the second gate electrode.

In an embodiment, the second light blocking layer may further include a second counter gate electrode overlapping the second gate electrode.

In an embodiment, a gate low voltage line may be connected to the second counter gate electrode through a contact hole in an insulating layer.

In an embodiment, the number of the second finger portions may be greater than the number of the first finger portions.

According to the display device of the present disclosure, the output of a driver can be stabilized and the size of the driver can be reduced.

The effects of the present disclosure are not limited to the aforementioned effects, and various other effects are included in the present specification.

Advantages and features of the present disclosure and methods of achieving the same will become apparent with reference to the exemplary embodiments described below in detail in conjunction with the accompanying drawings. However, the present disclosure is not limited to exemplary embodiments described below, and may be implemented in different forms. Exemplary embodiments will be provided to make the present disclosure thorough and allow one of ordinary skill in the art to which the present disclosure pertains to recognize the scope of the present disclosure, and the present disclosure will be defined by the scope of the claims.

When an element or layer is referred to as being “on” another element or layer, it includes both a case in which the element or layer is directly on another element or layer and a case in which the element or layer is on another element or layer with the other element or layer interposed therebetween. The same reference numbers indicate the same components throughout the specification. Shapes, sizes, proportions, angles, numbers, and the like, disclosed in the drawings for describing exemplary embodiments are examples, and thus, the present disclosure is not limited to those illustrated in the drawings.

It will be understood that, although the terms “first”, “second”, and the like may be used to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another component. Accordingly, a first component discussed below could be termed a second component without departing from the teachings of the present disclosure.

Each feature of the various exemplary embodiments of the present disclosure may be partially or entirely coupled or combined with each other, and is technically capable of various interlocking and driving, and each exemplary embodiment may be implemented independently of each other or may be implemented in combination.

In the specification, “A and/or B” represents the case of A, B, or A and B. In addition, in the specification, “at least one of A and B” represents the case of A, B, or A and B.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.

is a perspective view of a display device according to one embodiment.

The terms “upper.” “top” and “top surface” as used herein refer to an upward direction (i.e., a third direction DR) with respect to a display panel. The terms “lower,” “bottom” and “bottom surface” as used herein refer to a downward direction (i.e., a direction opposite to the third direction DR) with respect to the display panel. Further, “left”, “right”, “upper” and “lower” refer to directions when the display deviceis viewed from above. For example, “left” refers to an opposite direction of a first direction DR, “right” refers to the first direction DR, “upper” refers to a second direction DR, and “lower” refers to an opposite direction of the second direction DR.

The display devicedisplays an image on a screen through a display area DA, and various devices including the display area DA may be included therein. Examples of the display devicemay include, but are not limited to, a smartphone, a mobile phone, a tablet PC, a personal digital assistant (PDA), a portable multimedia player (PMP), a television, a game machine, a wristwatch-type electronic device, a head-mounted display, a monitor of a personal computer, a laptop computer, a car navigation system, a car's dashboard, a digital camera, a camcorder, an external billboard, an electronic billboard, various medical devices, various inspection devices, various household appliances such as a refrigerator and a washing machine including the display area DA, an Internet-of-Things device, and the like.

In addition, the display devicemay be a light emitting display device such as an organic light emitting display device using an organic light emitting diode, a quantum dot display device including a quantum dot light emitting layer, an inorganic light emitting display device including an inorganic semiconductor, and a micro light emitting display device using a micro light emitting diode. Hereinafter, an organic light emitting display device will be described as an example of the display device, and the organic light emitting display device applied to the embodiment will be simply referred to as the display deviceunless special distinction is required. However, the embodiment is not limited to the organic light emitting display device, and other display devices mentioned above or known in the art may be applied within the same scope of technical spirit.

The display devicemay include a display panel, a display driving circuit, and a circuit board.

The display panelmay, in plan view, be formed in a rectangular shape having short sides in a first direction DRand long sides in a second direction DRcrossing the first direction DR. The corner where the short side in the first direction DRand the long side in the second direction DRmeet may be rounded to have a curvature or may be right-angled. The planar shape of the display panelis not limited to the rectangular shape, and may be formed in another polygonal shape, a circular shape or an elliptical shape. The display panelmay be formed to be flat, but embodiments are not limited thereto, and for example, may include a curved portion formed at left and right ends and having a constant curvature or a varying curvature. Alternatively, the display panelmay be formed flexibly so that it can be curved, bent, folded, or rolled.

The display panelmay be divided into a display area DA displaying an image or video and a non-display area NDA disposed around the display area DA, in plan view.

The display area DA may include a plurality of pixels. The pixel is a basic unit for displaying a screen. The pixels may include, but are not limited to, a red pixel, a green pixel, and a blue pixel. The pixels may further include a white pixel. The plurality of pixels may be alternately arranged in plan view. For example, the pixels may be arranged in a matrix, but the present disclosure is not limited thereto.

The non-display area NDA may be disposed around the display area DA. A black matrix may be disposed in the non-display area NDA to prevent light emitted from adjacent pixels from leaking out. In addition, the non-display area NDA may include a driver for controlling or driving a plurality of pixels and a plurality of lines for applying an electric signal to each of the plurality of pixels. This will be described later in conjunction with.

The non-display area NDA may surround the display area DA as illustrated in. That is, the display area DA may be formed in a quadrilateral shape, and the non-display area NDA may be disposed around four sides of the display area DA. However, the present disclosure is not limited thereto, and the display area DA may be partially surrounded by the non-display area NDA. For example, the non-display area NDA may be disposed only around three sides of the display area DA. In this case, the fourth side of the display area DA may form an edge of the display device.

The display driving circuitmay be formed as an integrated circuit (IC) attached onto the display panel by a chip on glass (COG) method, a chip on plastic (COP) method, or an ultrasonic bonding method, but the present disclosure is not limited thereto. For example, the display driving circuitmay be attached on the circuit board.

The circuit boardmay be attached onto the pads DP using an anisotropic conductive film. Accordingly, lead lines of the circuit boardmay be electrically disposed on the pads DP. The circuit boardmay be a flexible printed circuit board, a printed circuit board, or a flexible film such as a chip on film.

is a plan view of a display device according to one embodiment.is a block diagram of a display device according to one embodiment.

Referring to, sub-pixels PX, and gate lines GL, emission lines EML, data lines DL, and a driving voltage line VDL connected to the sub-pixels PX may be disposed on the display panel. The gate lines GL and the emission lines EML may extend in the first direction DR, and the data lines DL and the driving voltage line VDL may extend in the second direction DRcrossing the first direction DR. The driving voltage line VDL may extend in the second direction DRin the display area DA. The driving voltage lines VDL may be connected to each other in the non-display area NDA.

Each of the pixels PX may be connected to at least one of the gate lines GL, one of the data lines DL, at least one of the emission lines EML, and the driving voltage line VDL. In, it is illustrated that each of the pixels PX is connected to three gate lines GL, one data line DL, one emission line EML, and the driving voltage line VDL, but the embodiments are not limited thereto. For example, each of the pixels PX may be connected to two or fewer gate lines GL instead of three gate lines GL, or may be connected to four or more gate lines GL.

Each of the pixels PX may include a driving transistor, at least one transistor, a light emitting element, and a capacitor. The driving transistor and the at least one transistor may be a thin film transistor. The at least one transistor may be turned on or off according to a gate signal applied from the gate line to act as a switching element. For example, when a transistor disposed between the data line and the gate electrode of the driving transistor is turned on by a gate signal, the data voltage of the data line may be applied to the gate electrode of the driving transistor. The light emitting element may be an organic light emitting diode including a first electrode, an organic light emitting layer and a second electrode. The light emitting element may emit light according to the driving current of the driving transistor. The capacitor may serve to keep constant the data voltage applied to the gate electrode of the driving transistor.

As illustrated in, the display driving circuitmay include a timing controller, a data driver, and a plurality of voltage lines.

The timing controllermay receive digital video data DATA and timing signals from the circuit board. The timing controllermay generate a plurality of gate control signals GCS, GCS, and GCSfor controlling an operation timing of each of a plurality of gate drivers,, andaccording to the timing signals, may generate an emission control signal ECS for controlling an operation timing of an emission control driver, and may generate a data control signal DCS for controlling an operation timing of the data driver. For example, the timing controllermay generate the first gate control signal GCS, the second gate control signal GCS, and the third gate control signal GCSaccording to the timing signals. Further, the timing controllermay output the first gate control signal GCSto the first gate driver, output the second gate control signal GCSto the second gate driver, and output the third gate control signal GCSto the third gate driver.

The timing controllermay output the gate control signals GCS, GCS, and GCSto the plurality of gate drivers,, and, respectively, through the plurality of gate control lines GCL, and may output the emission control signal ECS to the emission control driver. The timing controllermay output the digital video data DATA and the data control signal DCS to the data driver.

The data drivermay convert the digital video data DATA into analog data voltages to output the analog data voltages to the data lines DL through fan-out lines FL.